Method to make a photoconductor drum having an overcoat using a dual curing process

Abstract

A method of preparing an organic photoconductor drum having a protective overcoat on its outermost surface is provided. In an example embodiment, a photoconductor drum having an electrically conductive substrate, a charge generation layer, a charge transport layer and an outermost protective overcoat layer is provided. The photoconductor drum is cured using a two-step process. The first curing step applies either ionizing irradiation, such as with an electron beam or by gamma rays or applies non-ionizing irradiation such as ultraviolet light to the photoconductor drum. A mask is sized and placed over the print area of the initially cured photoconductor drum, thereby exposing the outermost edges of the photoconductor drum. The outer edges of the masked photoconductor drum is then exposed to a second curing step using ultraviolet light irradiation.

What is claimed is: 
     
       1. A method of preparing an overcoated photoconductor drum comprising:
 providing an electrically conductive substrate; 
 preparing a charge generation layer dispersion; 
 coating the charge generation layer dispersion onto the electrically conductive substrate and drying the charge generation layer dispersion coated on the electrically conductive substrate to form a charge generation layer; 
 preparing a charge transport layer solution; 
 coating the charge transport layer solution over the charge generation layer and curing the charge transport layer solution coated on the charge generation layer to form a charge transport layer; 
 preparing an overcoat layer formulation; 
 dip coating the overcoat layer formulation over the charge transport layer; 
 curing, in a first curing step, the overcoat layer formulation using a dose of electron beam ionizing irradiation to form an overcoated cured photoconductor drum; 
 shielding with a mask sized to cover a print area of the overcoated cured photoconductor drum and thereby expose an outer edge of the overcoated cured photoconductor drum located outside the print area; 
 curing, in a second curing step, the outer edge of overcoated cured photoconductor drum located outside the print area using ultraviolet non-ionizing irradiation exposure to produce an overcoated dual cured photoconductor drum; and 
 thermally curing the overcoated dual cured photoconductor drum in an oven. 
 
     
     
       2. The method of  claim 1 , wherein the electron beam ionizing irradiation dose is between about 10 kGy and about 100 kGy. 
     
     
       3. The method of  claim 2 , wherein the electron beam ionizing irradiation dose is between about 20 kGy and about 40 kGy. 
     
     
       4. The method of  claim 1 , wherein the ultraviolet non-ionizing irradiation exposure is between about 0.1 J/cm 2  and about 2 J/cm 2 . 
     
     
       5. The method of  claim 1 , wherein the mask is aluminum. 
     
     
       6. The method of  claim 1 , wherein the overcoated dual cured photoconductor drum is thermally cured in the oven at 120° C. for 60 minutes.